Multiple unit machine tool



Oct. 28, 1947. J. H; MANSFIELD Q 2,429,938

MULTIPLE UNIT MACHINE TOQL Filed Oct. 4, 1941" v 7 Sheets-Sheet 1- O 8, 19 7 J. H. MANSFIELD 2, 29,938

MULTIPLE UNIT MACHINE TOOL Filed Oct. 4, 1941 7 Sheets-Sheet 2 w B2 (fl/0'30)? QK Wans/ie/d gflT-rowgw Oct. 28,. 1947. J. MANSFIELD MULTIPLE UNIT MACHINE TOOL 7 Sheets-Shet 5 Filed Oct. 4, 1941 af/e/d 4 M QaT-romgys I Oct. 28,1947.

J. H. MANSFIELD MULTIPLE UNIT MACHINE TOOL Filed 001;. 4, 1941 7 Sheets-Sheet 5 STOP MAIN sTAR'i' Oct 28, 1947. J. H. MANSFIELD ,93

MULTIPLE UNIT MACHINE TOOL 'rTomayJ I Oct- 1947- J. H. MANSFIELD MULTIPLE UNIT MACHINE TOOL 7 Sheets-Sheet 7 Filed Oct. 4, 1941 N V L N TO L (fact son Q1. Warns/7e /d TTowgzys Patented Oct. 28, 1947 UNITED STATES PATENT OFFICE Judson H. Mansfield, Rockford, 111., assignor to Greenlee Bros. & 00., Rockford, 111., a corporation of Illinois Application October 4, 1941, Serial No. 413,633

26 Claims.

The present invention pertains primarily to a novel multiple unit type of machine tool, that is to say, to a machine tool in which there are a plurality of separately movable units or tool heads, each of which has its own individual tool drive and feed mechanism for traversing the unit. In machines of this type, various tools may be provided on difierent ones of the units, for example, drills on some, taps on others, facing tools on still others, etc.

One object of the invention is to provide a machine tool of the type indicated, embodying a novel and improved arrangement for effecting a predetermined programed and coordinated feeding of the various units into and out of the operative relation witha work piece.

More specifically, it is an object to provide a machine of the type indicated which embodies a novel control arrangement for efiect-i-ng a, programed operation of the units in which different selected ones of the units participate in successive cycles of operation of the machine.

Another object is to provide a machine tool of the type set forth which can, simply by the manipulation of a control device as distinguished from a disassembly of the controls and new setup of the same, be conditioned at will to execute any selected one of a plurality of programs of cyclic operation.

Another object is to provide a multiple unit type of machine in which the units are advanced, by individual feed mechanisms, into operative relation with the work and retracted upon completion of a predetermined machine operation, a novel interlock arrangement of such character that a succeeding feed cycle for the units can only be instituted after the units have each completed a predetermined advance and retraction cycle movement. In other words, the interlock is such that the units must not only all be in their proper starting positions before a new cycle can be initiated, but must also have fully executed their previous cycle.

Still another object of the invention is to provide a machine embodying an interlock arrangement of the character indicated in the immediately preceding statement of object, and which is additionally adapted for a type of programing in which only a portion of the total available units are utilized in certain ones of the successive cycles. More specifically, provision is made for accommodating a condition .in which less than all the units participate in a particular cycle .so that the fact that there are such non-participating units, and which therefore remain at rest,

2 will not interfere with the interlocking which compels all of the participating or selected units to completely execute their cycle of movement before the next cycle can be instituted.

Further objects and advantages of the invention will become apparent as the following description proceeds, taken in connection with the accompanying drawings, in which:

Figure l is .a plan view of a machine tool emleodying the invention.

Fig. .2 is a fragmentary front elevation of the leithand portion of the machine as viewed in Fig. 1., showing particularly unit 1 of the machine.

Fig. 3 is a fragmentary rear elevation of the lefthand portion of the machine shown in Fig. 1, showing particularly unit .2 of the machine.

Fig. 4 is a generally schematic perspectivelayout of the table indexing mechanism and parts driven in unison therewith.

Fig. l is a detail end elevation of the intermittent gearing included in the mechanism of Fig. i.

Fig. 5 is an .endelevation of a rotary switch actua-ting mechanism, and series of switches associated therewith, driven in timed relation with the table indexing mechanism.

Fig. 6 is aplan view, partially in horizontal section, of the program switch mechanism for the machine control, housed in a casing at the left end of the machine bed, as viewed inFig. 1.

Figs. 7 and '8 are, respectively, :a front elevation and end elevation, partially in section, of the program switch mechanism of Fig. 6,

Figs. 9 and 10 are wiring diagrams of the electrical control system for the machine tool,

these two figures being adapted to be placed end to end with Fig. 10 below Fig. 9., to show the complete circuit.

Fig. .11 is a cycle chart for the control system, showing the open or closed condition of various switches during successive cycles in the program of operation for the machine.

Fig. 12 is a development of the movable contacts in the master controller for the control system.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it isto be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions fallin within the spirit and scope of the invention as expressed in the appended claims.

3 General organization of the machine In the particular machine (Fig. 1) selected for exemplification of the invention, there are six individually movable tool supports shown as units or tool heads, I to 6 inclusive, each having a metal removing tool or tools thereon and all arranged to operate on a single work piece (not shown). These units are distributed generally circularly about a centrally located movable work support, shown in the form of a rotatably indeXible table I. Each of the six units is of what is commonly known as the self-contained type and is adapted to exceute, independently, a cycle of movement in which it advances toward the work and then returns to its starting position. In the present instance each unit advances at a rapid approach rate, then at a slower feed rate while its tool is operating on the work, and is then retracted at a rapid return rate. For this purpose each of the units has its own individual tool drive and unit propulsion mechanism, as is common practice in such multiple unit machines, so that the operation of each unit is sufficiently independent of the others that it can be readily suited to the length of cutting advance and speed requirements of the particular operation which its tool or tools perform. The number, angle of approach and. particular location of the units relative to the work piece are so chosen as to accommodate the requirements of a particular piece of work. In the present instance, the unit I is mounted to slide angularly downward toward the work (see also Fig. 2) while the other units slide horizontally.

All of the units I to 6 are supported from a massive bed structure, this structure comprising a rectangular main bed 8, in the center of which is mounted the table I on a revoluble upright table drive spindle 9, suitably journaled in the bed. The units I, 2, 4 and 5 are disposed at the four corners of the top surface of the main bed 8 (Fig. 1), while the other two units 3 and 6 are supported on bed wings IEI and II bolted to the opposite sides of the main bed 8. Each of the units I to 6 is traversable along an individual guideway I2 therefor, fixed to the corresponding part of the bed structure. In the case of the unit I, a wedge-shaped support I3 (Fig. 2) is interposed between the main bed 8 and the units guideway I2 so that the latter will be inclined for the desired angle of approach of the unit toward the work on the table 1. Of course, such supplemental mounting blocks or the like may be used for the guideways of the other units to provide any angle of approach for the same, relative to the work, required for a particular work piece.

In brief, the controls for the machine are such that the units are caused to move automatically in accordance with a predetermined program. In each main division of the program of unit operation, predetermined ones of the units are caused to execute their individual cycles of movement, that is, rapid approach toward the work, a slower or feed speed advance while their tools are operating on the work, and rapid return back to their initial position upon completion of the machining operation. Intermediate each such main division of the program of unit operation, the table I is'indexed through a predetermined increment of rotation to present spaced portions of the work piece on it to the various units successively. Furthermore, the control system is such that the units, as well as the table I, can

'of their respective units.

be operated individually rather than in the course of a program of automatic operation. Before proceeding further with a description of the control system, the exemplary construction of the units and table will be examined with particular reference, however, only to the control devices of the actuators therefor which are associated directly with the main control system.

Construction of the individual units The details of the individual units I to 6, included in the machine illustrated, form per se no part of the present invention, and since units of this general self-contained type are wellknown in the art, simply a brief description will suifice. All of these six units are essentially similar in construction. Thus, each includes a slide or carriage I4 traversable along its corresponding guideway I2. On the forward ends of the sildes I4 are casing structures I5 and 20 for the respective units I to 6. The forms of the individual ones of these tool head casings are such as to adapt them to accommodate the particular tools assigned to the corresponding units. Thus, in the present instance the units I, 2 and 4 have spindles ZI adapted to receive rotatable rough boring and facing tools, the units 3 and 6 having rotatable drill spindles 23, while the unit 5 has three such rotatable drill spindles 24. It will be appreciated by those skilled in the art that, of course, a wide variety of different forms and numbers of rotatable tools may be provided on the various tool heads.

Any one of a number of Well-known forms of drive and propulsion mechanisms of either the electric or hydraulic types may be utilized for the several units. For present purposes the primary requirement is simply that they be capable of control, as to starting and preferably stopping, from a remote point as, for example, through the use of electromagnetically operated switches or valves. In the present instance electric motors, started and stopped by remotely controlled relays or contactors, are used for driving the tool spindles; and hydraulic propulsion systems, started and reversed by remotely controlled valve-operating solenoids, are used to traverse the units. Thus individual electric drive motors 25 to 3!! are provided for the respective units I to 6 (Fig. 1). These motors are mounted on the unit slides I4 and are connected through suitable gear connections (not shown) in the casings I5 to 20 to drive the tool spindles Additionally, these motors serve to drive fluid supply pumps (not shown) for hydraulic type feed or propulsion mechanisms of their respective units. These hydraulic feed mechanisms have not been detailed, since they may be of any one of a variety of forms available on the market today and which, per se, form no part of the present invention. It is sufiicient to note that the feed mechanism of unit 2, shown in Fig. 3, and which is typical of those for the whole series of units, comprises a hydraulic actuator in the form of a cylinder 3i rigid with the slide I4 and having slidable in it a piston 32 fixed to the bed 8. Thus as pressure fluid is supplied to the left end of the cylinder 3| (as viewed in Fig. 3) and exhausted from the righthand end, the slide I4 is traversed to the left, i. e., advanced toward the work; and similarly, as fluid is supplied to the righthand end of the cylinder 3i and exhausted from the lefthand end, the slide I4 is retracted to the right.

Pressure fluid for this purposeis, as noted above,

supp ied from a suitable pump units motor 26.

Control of the pressure fluid s efiected by a suitable valve, mechanism housed within casing 33. fixed on the slide I4. Since hydraulic control valve mechanisms of the general type here contemplated are commonly available on the market and their construction well known (for a publication giving details of the same see I-Iydraulic Controls on Machine Tools published in 19.40 by General Motors Institute, and particularly the Vickers System in Sec. C.Unit 4,

driven by the page 7) only the general program of operation need be detailed here, together with the actuating devices therefor which form a part of the general control system that enters into the present invention.

In brief, the valve mechanism housed in the casing 33 has four positions, viz: a neutral or stopped position in which supply of fluid to the cylinder 3! is cut off, a rapid approach position in which fluid is supplied at a high volumetric rate for advance of the slide is, a slow feed position in which fluid is supplied to the cylinder 3! at a lower volumetric rate for a slower or feed advance of the slide, and finally a rapid return position in which fluid is supplied to the cylinder for a rap d retraction of the slide M. The valve mechanism can be shifted to any of such four positions by a hand lever 34 swingably mounted on the side of the casing 33, or by automatic-operation instrumentalities including a pair of solenoids hereinafter detailed, in a casing 35 and a plunger 36 operated by dogs 31 and 38 adjustably fixed to a rail 39 on the side of the bed 8.

At the start of a cycle of unit movement, momentary energization of the starting solenoid shifts the valve mechanism to its rapid approach position; then. as the slide [4 moves forward, elevation of the plunger 36 by the dog 31 shifts the valve mechanism from its rapid approach position to its feed position. At the end of the forward stroke of the unit a limit switch is closed to energize the reversing solenoid momentarily so that it shifts the valve mechanism to its rapid return position, whereupon the slide M is caused to retract. Finally, when the slide l4 reaches its initial position, the valve mechanism is shifted back to its neutral position by engagement of the dog 38 with the plunger 35 to stop the unit.

The solenoid and other electrical connections in the master control system are shown in the wiring diagram, Figs. 9 and 10, and are hereinafter detailed, though it may be convenient to note at this point that the starting or unit forward solenoids are identified as UFI, UFZ, UF3, UFA, UF5 and UF6, and the unit reverse solenoids as URI, UR2, UB3, UB4, UB5 and UB6 for the units l to 6, respectively. In Fig. 2 is shown the reversing limit switch LSlS for the unit I and which is typical of the location of the similar switches, mentioned generally above, for all of the units. This switch LS|3 is mounted stationarily adjacent the unit I and is a norm-ally open switch. It is closed at the extremity of forward motion of the unit by a dog 39 adjustably mounted on the side of the latter opposite the valve mechanism. Incidentally, it may he noted here that the similarly located reversing limit switches for the units 2 to 6 are identified in the wiring diagram (Fig. as LS23, L833, L343, L853 and L563, respectively.

Table indexing mechanism 3 connected through a speed reduction gearing 4,1,

and a worm and worm wheel 42, 43 to a rotatable shaft 44. The latter shaft is connected through an intermittent gearing, designated nerally at 5, with a shaft 46, which is in turn connected through bevel gears 41, 48 to the table spindle 9,. The intermittent gearing 45 may be of any suit.- able well-known form and is shown as including a driver arm 49 fixed on the shaft 44 and having a roller 50 journaled on its outer end. The driven element 5| of the intermittent device comprises a disk fixed on the shaft 46 and having four radial slots 52 in its outer face, merged at their inner ends (see Fig. 4* for a face view of the member 51;). Upon each revolution of the shaft 44 the roller 53 enters the outer end of one of the grooves 52, passes down the same and then outter-turn. Consequently, each revolution of: the

shaft 44 advances the shaft 46, and thereby the table 1, through one step of the movement. The ratio of. the gears ll, 48 is so chosen, in the present machine, that the table F will be moved through one-fourteenth of a complete revolution during each step of its advance.

To locate the table accurately in its various. index positions, any suitable locating or locking means may be utilized, and of which a number are well-known in the art. In the present instance, such a mechanism has been shown generally schematically in the form of a locating pin 53 which is projectable vertically into registering ones of a series of fourteen holes 54 corresponding to the various index positions of the table. The pin 53 is pivotally mounted on the outer end. of a bell crank lever 55, which is carried, by a stationarily mounted pivot pin 58. The arms of the bell crank 55 are bifurcated, and the lower one is pivotally connected to an endwise-movable. shifter rod 51.

The rod 51 is shifted endwise in timed relation with the indexing of the table (to raise and lower the pin 53) by means of a barrel, cam 58 fixed on the shaft id. This cam 58 has a peripheral groove 59 in which is received a cam follower roller on a pin 68 journaled in a swinging arm 6!. The. latter is carried by a pivot 62. The outer end of the arm 3! is received between. a pair of collars t3 fixed on the rod 51. The cam groove'59 is contoured so that as the shaft. 44 begins to revolve from the position shown in Fig. 4, the arm 6| will swing to the right, thereby free ing the pin 53 from the table 7. As the rotation of the shaft 44 continues, the intermittent gearing mechanisms driver roller 53 engages the driven member 5| just before the pin is freed from the table. The cam groove 59 is contoured so that the pin is retained out of engagementv with the table until the step of indexing motion of the latter is almost completed and just before the roller 53 leaves contact with the driven member 5|, and thereafter the cam groove 59 is contoured to swing the arm 8| back to the left, and thereby re-engage the pin with the corresponding hole 54. during the completion of the revolution of the shaft 44.

Various means may be provided for insuring accurate location of the table in the precise angular position required. In the present instance thecontrol system is arranged, through switching 'mechanism hereinafter detailed, to open-circuit.

the indexing motor 45 at the completion of the indexing movement of the table and then to plug it to insure immediate stoppage. In other words, the motor is, upon stoppin energized for reverse rotation and remains so energized until the instant at which such reverse rotation actu ally starts and at which time a plugging switch '64 (Fig. l) opens to de-energize the motor. Plugging switches for the general purpose noted are well known in the art, and the switch 54 has been generally schematically illustrated in Fig. 4. As there shown, it comprises a stationary contact 65 coacting with a movable contact '55 on an arm having a hub 51 loosely journaled on a shaft E3. Frictionally engaging the face of the hub 51 is a disk 69 fixed to the shaft 68. The latter shaft is driven by a belt 153 and pulleys 1! from the motor 40.

As the shaft of the motor 49 revolves in the direction of the arrow 12 in Fig. 4, which is the direction of motor rotation utilized for advancing the table, the movable switch contact 56 is urged into closed position with relation to the stationary contact 65 by the frictional engagement of the disk 69 with the hub E1. When it is desired to stop the motor it is energized for rotation in a reverse direction through a circuit including the plugging switch. Then as soon as the motor begins to revolve in the opposite direction the plugging switch opens and the motor is thus stopped.

A group of five control switches (see Fig. 5) is arranged to be actuated in timed relation with the rotation of the table indexing 15 and, accordingly, the construction of their actuator may conveniently be described at this point since it is driven by the tables indexing mechanism. Ihe actuator comprises a disk 13 (see also Fig. 4) fixed to the outboard end of the motor-driven shaft 44. Fixed at suitable points on this disk, and projecting radially from it are five dogs 14, 15, 15, 11 and 1% which are adapted to actuate respective ones of an adjacent series of switches L813, L812, L816, L815 and L811. The dogs are all displaced from each other in a direction axially of the shaft 44 a sufficient amount that the associated switches can be mounted so that only the corresponding dog will engage the actuator of the same as the series of dogs revolves.

As indicated in Fig. 5, the series of switches mentioned just above are all of the form commonly used for limit switches and each embodies swingable actuator arm 15 having a roller on its outer end adapted to be engaged by the correspending dog, the arms being spring-urged toward the dogs. Of these five switches, all except the switch L815 have a single set of contacts, and those of all except L812 are normally open and are closed when the associated dog moves the switchs actuator arm 19. The switch L812 has normally closed contacts, opened by its dog and the switch L815, has a pair of alternatively closable contacts lL815 and ZL815 (see Fig. 9). The contacts of the switch L815 are normally urged to a position in which the contact 5L815 is closed and the contact 21815 opened. The dog 11 engages the actuator arm of the switch L815 when the shaft 44 is in such angular position that the locating pin 53 is projected upward in engagement with the table 1. Accordingly, the contact IL815 is closed at all times when the pin 53 is not in engagement with the table and is open when the pin is properly engaged with the table. As will hereinafter appear, the switch L815 is used as an interlock to prevent operation of the 8 units Ito 5, except when the locating pin 53 is in engagement with the table 1, thus showing that the table is in a properly indexed position. It should be observed that the switch L815 is actuated by its dog 11 somewhat in advance of the time that the shaft 44 reaches the position shown in Fig. 5 and remains actuated by its dog until the shaft does reach such position. On the other hand, the switch L813 is closed momentarily by its dog 14 just before the shaft 44 reaches the position shown, but is freed to reopen when the shaft stops in such position. The timing is such as to give an overlap of the operation of switches L815 and L813 so that the switch L813 will be closed coincidentally with contacts 2L815, and then reopened.

The functions of the other four switches L81] to L814 described just above will be more fully developed in connection with the description of the operation of the control system as a whole. It is suflicient for present purposes to note that the switch L811 is closed by its dog 18 during each indexing movement of the table and serves to pre-set' certain interlock contactors for the units. Opening of the switch L812 by its dog 15 stops the table indexing motor 40. The momentary closure of L813 by its dog 14 initiates the forward movement of the units, but is connected in series (see'Fig. 9) with the contacts 2L815 of the switch L815 so that it will only be efiective to initiate movement of the units when the locating pin 53 is properly engaged with the table 1. The switch L814, like the switch L815, is shifted to closed position by its cooperating dog when the table-locating pin 53 is properly engaged with the table, or in other words, when the table is properly set in one of its indexed positions. The switch L814 is, however, connected in a different portion of the control circuit (see Fig. 9) from that which includes the switch L815 and serves, in general, as an interlock which permits movement of the units only when the table is properly positioned, during operation of the units individually, as distinguished from their operation in the course of a program of automatic operation.

Master controller for selection ogf general type of operation Provision has been made for conditioning the machine as a whole for various types of operation. In the instant machine, four general types of operation are optionally available to the user, and these are:

(1) Automatic cycle operation. (2) Hand-feed operation.

(3) Unit-feed operation.

(4) Hand index operation.

A master controller is provided for the machine and has four positions or settings corresponding to the four types of operation noted above. The master controller is housed within the bed 8 and is operable by a four-position hand lever 22 on the front of the machine (see Fig. 2). The controller itself is of conventional construction for such devices and its contacts are shown in development in Fig. 12. As indicated in the latter figure, there are seven bridging contacts Bi to B1, movable as a group, and'seven pairs of stationary contact points CI to C1, said bridging contacts being movable endwise of the set of stationary contacts to the four positions indicated by the legends in Fig. 12 and which correspond to the four types of operation listed for the machine the contacts C4 are closed; and in the hand index position only the contacts C5, C5 and C? are closed. The circuits connected to the contacts Cl to Cl are shown in Figs. 9 and and more fully described hereinafter.

In brief, when the master controller is set in its automatic cycle position the machine is conditioned for operation in accordance with a predetermined program which is executed from b ginning to end completely automatically by the machine. In the course of this program the table 1 is rotatably indexed through fourteen steps to complete one full revolution, and in each of the fourteen positions thereof certain predetermined ones of the units l to 6 are caused to execute their cycles of movement heretofore described, so that their tools operate upon the corresponding portions of the work piece on the table presented to such units. The hand feed setting is used when it is desired to have the units repeat their cycles for only some one particular step in the over-all program mentioned just above. In the third, or unit-feed type of operation, the drive motors for desired individual ones of the units may be set in operation by corresponding push buttons H to M, inclusive (see Fi 9), and the units traversed by manipulation of their control levers 34 for the valve mechanisms heretofore noted. In the fourth or hand index type of operation the table 1 can be indexed step-by-step through any distance desired without setting in operation any of the units. The last three types of operation are used primarily in setting up the machine for a new work piece. The controls and their operation for effecting all four of these types of operation will appear in detail hereinafter.

Program control for automatic operation As noted above, when the master controller is in its automatic cycle position the machine is adapted to operate throughout a complete program of automatic operation. Also of particular importance in the present invention is the provision of means by which the machine can be readily conditioned to execute any desired one of several such programs of automatic operation. In the exemplary machine, provision is made for two alternately available programs. This makes it possible to arrange one program for carrying out a series of operations on one work piece, and a second program for carrying out either a second series of operations on the same workpiece or a second series of operations on a diiferent form of work piece. In this way, wastage of time for set-up of the machine is avoided, since with the present arrangement a shift from one program to another entails no more than simply shifting a hand lever, as hereinafter described. It will be appreciated by those skilled in the art that set-up time represents not only the cost of highly skilled labor in reconditioning the machine for a difieren't operation, but also loss of output from a very expensive machine tool during the time that 'it is idle.

In brief, the programing in the present machine is accomplished by means of a cam mechanism driven in timed relation with the indexing of the table I. For each index step of the table the cam mechanism sets up the controls automatically in such manner that predetermined ones of the units are conditioned for operation.

10 To make possible more than one program, a corresponding plurality of sets for the cams are provided.

In the exemplary construction, the cam mechanism, and the control switches which it operates, are housed in a casing 8| at the left end of the machine bed 8 (Figs. 1 and 2). The cam mechanism itself (see Figs. 6, '7 and 8) comprises a cam shaft 82 extending longitudinally of the casing and having keyed on it two sets of peripheral cams 83 and 84, respectively, and various groups of these cams-from the two sets are separated by suitable spacer collars 85. These two sets of cams are positioned to be used selectively to actuate an associated set of electric control switches comprising switches L822, L832, L842, L852 and L852, corresponding to units 2 to 6, respectively, and a group of three additional control switches LSBI, L882 and L883. .No such switch need be provided for unit I since the exemplary machine happens to be set up in such a way that this unit participates in each step of both of the available programs, except in the final step of the second program, and inthis last step the unit 3 operates alone through the use of a special circuit controlled by the switch L883, rather than under the control of its usual unit switch L832, all of the unit switches being cut out of service at such time.

The switches L822, L832, L842, L852 and L862 are all normally open switches and have cam followers 86 on their upper ends (see Figs. 7 and 8) which, when thrust downward by the associated cam, close the corresponding switch. Of the other three switches, the switchv L883 is of the same single-contact, normally open type, but the switches L88! and L882 are of the doublecontact type. Thus, the switch L88! (see Fig. 10) has two mechanically interconnected alternatively closable contacts, ILSBI and 2L88l, while the switch L882 also has two alternatively closable contacts IL882 and 2L882 (see Fig. 9). The switches L88 I L882 and L883 also have actuators 86, operated by the associated cams. All of the eight switches noted are mounted on a bracket bar 81 (Figs. 6 and 7) within the housing Bl. The connections to the various switches, hereinafter detailed, are shown in Figs. 9 and 10 where the cam mechanism associated therewith is also indicated diagrammatically.

Longitudinal shifting of'the cam shaft 82, together with a short rocking motion of it, is utilized to condition one or the other of the sets of cams 83 or 84 to operate the associated series of switches. For this purpose, the cam shaft 82 is journaled in a pair of swingable bracket arms 88 fixed on a shifter rod 89, which is mounted for longitudinal as well as rocking movement in bearings 98 in the end walls of the housing 8| (Fig. 6). A hand lever 9|, pinned to the rod 89 at 94, is utilized in shifting the rod endwise to one or the other of its two alternative positions. These two alternative positions are defined by a pair of slots Slit in a bracket 93 (Fig. 6). When the lever 9| is seated in the outermost one of the slots 93 as shown in Fig. 6, the cams 83 are in operative relation with the switches, and when the lever is pushed to the right, carrying the rod 89 with it, and seated in the other or innermost slot 93 the other set of cams 84 is positioned for operation. A locking screw 92 passing through the lever and threaded in a tapped hole in the root of the slot in which the lever is located holds the hand lever releasably in one or the other of the slots 93 In' l1 shifting the lever 9| from one slot to the other the screw 92 is released and the lever is pulled upward to free it from the slot, the rod 89 being thereby rocked, thus raising the cams to clear the switch actuators 86 (Fig. 8).

The cam shaft 82 is driven in timed relation with the table I, and like it, is indexed to four teen successive rotary positions in making a full revolution. For this purpose, the cam shaft 82 has a gear 95 fixed on one end thereof (Figs. 4 and 6) and meshed with a pinion 96 loosely journaled on the shifter rod 89. This pinion 90 is, in turn, driven from a bevel gear 91 fixed to it and meshed with a bevel gear 98. The latter gear is driven through a jointed shafting 99 (Fig. 4) from a bevel gear I meshing with a bevel gear I0l fixed on the table spindle 9.

The cams 83 and 84 are peripherally notched (see Fig. 8) and when a notch thereon is shifted into registry with the actuator roller 86 on the corresponding switch, the latter is permitted to move upward under the urging of its spring bias. 0n the other hand, when a lobe or projection on the cam contacts the actuator roller, the latter is thrust downward and the switch contacts closed. Each of the sets of cams 83 and 84 is so contoured that for each of their fourteen successive positions certain desired ones of the unitcontrol switches L822, L832, LS42, LS52 and L552 will be closed. Through the use of control connections hereinafter set forth, the closure of such switches is utilized to condition the corresponding units for operation. The functions of the other three switches LS8I, LSBZ and LS83 appear hereinafter in connection with the description of operation of the general control system.

Interlocking system A fairly large number of interlocks are provided at various points throughout the machine to insure its safety of operation. The principal ones of these are outlined in the present section.

First to be noted is the means for insuring full retraction of each of the units or heads I to 6 prior to the institution of each indexing step of the table I. It will be appreciated that since the units have individual propulsion mechanisms, and may be set up to operate at different speeds and through different ranges of travel, that they will ordinarily not be returned to their idle stations coincidentally. Accordingly, it is necessary to interconnect their controls so that all of them must be fully retracted before the table I can be indexed. For this purpose a plurality of limit switches LSI I, LS2I, LS3I, LSM, LS5I and LSGI are provided for respective ones of the units I to 6 (see Fig. 9). The mounting of the switch LSII for the unit I is typical for all and is shown in Fig. 2. As indicated in the latter figure, the switch is stationarily mounted adjacent the unit and is disposed to be closed by a dog I02 adjustably mounted on the side of the units slide l4. Each of these switches embodies, respectively, normally open main contact ILSI I, ILSZI, ILSSI, ILS4I, ILS5I and ILSSI, as well as a normally closed auxiliary contact 2LSII, 2LS2I, 2LS3I, ZLSAI, ZLSEI and 2LS6I (Fig. 9). Engagement of the dogs I02 with the actuator arms of the respective switches causes the main contacts to close and the auxiliary contacts to open. In Fig. 9 the dogs I02 are indicated as so engaged, which is the condition which prevails when all of the units I to 6 are fully retracted and ready to start a cycle. The main contacts are all connected in series with each other so that all of them must be closed before a circuit can be completed through them for initiating operation of the tables indexing motor 40.

The auxiliary contacts ZLSI I, etc., noted above, serve to control corresponding ones of a set of pilot lamps I03 (Fig. 9). These lamps are mounted on a panel I04 (Fig. 2) on the front of the machine. Closure of a push button switch 0 (Fig. 9) sets up a supply circuit for the lamps and if any one of the auxiliary contacts is closed its corresponding pilot lamp will light. thereby indicating that its unit is not fully retracted. The operator can thereby readily inform himself of the particular unit or units which are not fully retracted at any time and which are therefore holding up indexing of the table.

The second and much important feature of the interlocking system to be noted is the means for insuring that the units programed for operation in any particular step of the program of automatic operation have, in fact, actually executed their cycles of movement before the table 7 can be indexed to its next position. In other words, the arrangement is such that if, say, units I and s are programed for operation at a particular point in a program they must not only be retracted before the table can be advanced a furter step, but must have also been fully projected forward prior to their arrival in such retracted position. Moreover, the interlocking for this purpose is such as to accommodate the programing of only selected ones of the whole series of units for participation in particular steps of the program. Upon reflection it will be seen that the latter factor introduces a prime difiiculty. In particular, the system cannot be merely such that the units complete an interlocking circuit by closing corresponding series connected limit switches when fully advanced, for, in that case, there would be no way to distinguish between a switch which was unactuated because of failure of a unit to advance. by reason of mechanical difficulty, from one which was unactuated bebecause of failure of the unit to advance by reason of its non-selection for that particular part of the program. These antithetical requirements have been reconciled in the present novel control system, as will more fully appear below.

With the foregoing in view, the control system comprises in addition to the limit switches LSI I, LS2I, etc.. responsive to the movement of the units into their retracted positions, another series of control devices dependent for their operation-upon the movement into their advanced positions of the units preselected in the immediately preceding operation of the programing device. In the present instance these additional control devices (see Fig. 10) are in the form of six interlock or timing contactors, TI, T2, T3, T4, T5, T5, provided for the respective limits I to 6. These contactors have respective main energizing windings TCMI, TCM2, TCM3, TCMA, TCM5 and TOME, as well as respective auxiliary release windings TCI, T02, T03, T04, T05 and T06. Each of the contactors has an endwisemovable armature I05, carrying a plurality of movable contacts in the usual manner for contactors, the armature being normally urged to the right (as view in Fig. 10) by a biasing spring I06. Momentary energization of the contactors main winding pulls the armature to the left, where it is held in position by a springurged mechanical latch I01. Energization of the auxiliary or release winding of the contactor releases the latch, thereby permitting the ar- 13 mature tosnap backto-the -rig ht,.sunder the-urge ing of its biasingspring; N26; to itsinitial: 12 SitlOIl:

In brief, the control system is such that during each indexing advance: of the-table.--1 the programing mechanism energizes, the release windings for the interlock contactors :oithe pare ticuslar um'ts preselectedfor: participationinthe next step of the programythus unlatc'hing their interlocking contactorstso as to!- render further operation: of the; indexing mechanism: subject to a relatchingfoperation in response torthe' movement of theunits into-their advancedpositions; Itis,; incidentally; the-closure of. switch. L8 71 dur ing theindexing of: the table by'thet actuator mechanism: therefor heretofore described: which sets: up the circuits-- to: permit such; energization of the. release windings" at? the proper time, the. circuits: therefor; bein hereinafter" detailed; When; the? units corresponding to the: unlatched' interlock contactors reach. their: points of: full advance; the resultant. closure of their: reversing limit switches (LS i=3; LS2 3, .LS3'3, LS4 3;.LS53I and ESG3rheremicro-described) causesthe" main-wind"- ings ofi the: unlatched1contactors to be energized, thereby-relatching such contactors; In. this way the' interlock; contactorsof: thexselected units for each step in the-program arerunlat'ched and then relat'chediwhen: the corresponding units have been: properly advanced-5. By: virtue" of this arrangementi all :of thec'on-tactors will be latched in at the end of the step of the program and the controL-systemis so'arrangedithat suchi glatch edin. condition for all. of: the; interlock; contactors isacondition precedentyto institution of the-next: succeedinga indexing: step. for the: table.

The thirdieature of the interlocking. system tog-beiparticularly noted. is the means for efiecting an: emergency retraction. of; the." unitsrini the event that any? of-them start; forward when the table isnot properlylocated in: one of its fourteen index positions; For this. purpose: switches 13814 and LSE'B; are. mounted: alongside the: units I and These. are normally open (Figs. 1 and: 21);. switchesand are closed by dogswe on the units during the initial portion of the advance. movement of the-latter. By circuits hereinafter set forth, closureof either of these switches ei-Tects arr emergencyretraction-of 'al'l of the units-if it happens that the-contacts [815 of switch LSlS -arealso closed' at the same time: It will be recalled that these contacts [LS- are closed whenever theloeati'ng pin 53 is not engaged with the table 7". O'nly-twoint'erlock switches LS M and" L835 are-included sinceone-or the other of the units-- l and 3 are utilizedin every stepof thetwopro grams for whichthe exemplary machine happens to be set up. Of course, with other program arrangements, additional switches of the same character could beprovided on other ones of the units.

Electric: control system The various automatic switches heretofore described: arezincluded in an integrated. control s-ys tem; Thecontr'ol: system is, in; a primary sense, se't up for-varioustypeszof operation by the use of the master: controller: heretofore noted, and

theexecu tiorx of these va-ri'ou types of operation: is inturn: instituted. or arrested by suitable ones These push button: switchesin tionof-this switch startsthe various drive motors 25 to 30 for the several units.

B. Master storp switch-Momentary actuationof this switch'stops the entire machine.

(2. Automatic cycle start switch-Momentary closure-of this switch initiates the automatic cycle of. operation for acomplete program;

D. Hand feed switch.Momentary closure of this switch institutes the operation of. the units for." the particular; step in the program corresponding. to the position of the table: so thatthe machine is caused to-execute that one stepof the program and; then come to rest. This control is used? in repeating a particular step in the program, for example, in setting up the machine. Thestable-must have been positioned through the use of the automatic cycle control rather than the handindex control so that the units and table will'be instepwith each other.

E. Hand-index switch.-Closur -of this hold down switch causes a step of indexing motion-for thetable '5 without afiecting the units [to ii.-

F' Emergency heverse switch-Momentary closure of this switch causes all of the units lto 6 to be'emergency retracted back to their initial oridl'e positions.

Upon reference-toFig. 2' it will be observed-that the control switch panel I99 is located adjacent the signal or pilot lamp panel It' l. Onthis latter panel are not only the set of pilot lamps m3 heretofore-noted for indicating the lack of full retraction in particular ones of the units, but also a set of six pilot lamps llil. These latter lamps (see Fig. 10') correspond to the respective units l-' to 6 and are controlled, respectively, by contacts 3T5; 3T2, 3T3, 3T4; 3T5 and 3T6 of theinterlock contactors T l te-T8.- T-he contacts notedare'open when the corresponding interlock contactors are released, and closed when they are latched in;

- Consequently, closure of a push button switch N.

in the supply circuit for the bank of pilot lamps H0", will cause those lamps to light whose corresponding interlock contactors are latched in, thereby indicating that those units whose lampsdo not light have not yet fully executed their forwardmovements. The push button switches O and. N for the sets of pilot lamps I03 and Ill] are also mountedonthep'ane1 we (Fig. 2 Aiurther pilot lam-p l l-t is mounted on; the switchpanel l-iifiiand is connected in a portion of the control circuit shown in Fig. 9, in a particularmanner which will herein-after appear, so that it will be lighted whenever the circuits are properly con'di tioned for institution of anautomatic cycle of operation by closure of the cycle start"-push buttoIr-O.

the control system'of Figs; 9 and 10-current is supplied for all of the motors as well as for the control circuits per so from a common source'oi 1 current; As there-indicated; the drive'motors' 25' to 311 for the respectiveunits are uni-directional threes-phase motors fed from supply lines L1, L2;

and ha, while-the-index motor 49 is shown as areversible three-phase motor. Current for the control circuitsis supplied at a suitable low voltage" through a step-down transformer H2 having a primary winding I i 3- (connected across supply lines Li-and' llz) and a-secondary'winding- I'M-Z One terminal of this secondary winding is connected: to a low voltage supply line H5 and the other to a line i i'lithrough the stop switch l3; The'line H5 i's-in turn connectedto a supple-- niental'isupplylin Hi1 throughcontact B1 of the master controller. Thelines lflsandi flfi'are con tinnedonto: Ei'g. lofandthe devices shown. in the latter figure are energized by connecting them across these lines.

Suitable relays and contactors are provided in the control system for controlling various portions thereof. Thus, each of the drive motors to 30 (see Fig. 9) is controlled by a corresponding one of a set of motor contactors Mi, M2, M3, M4, M and M5. The reversible indexing motor 40, on the other hand, has two contactors IMF and IMR associated therewith and which, respectively, connect it for forward and reverse rotation. The unit forward solenoids UP! to UF5, heretofore noted, are included directly in the control circuit (Fig. 9), but the unit reverse solenoids UR! to URB (Fig. are energized indirectly through the medium of respective unit reversing relays UTRI to UTRt. Moreover, the control circuit includes six intermediate relays or contactors, namely, a master start relay MS, an automatic feed relay AF, a master feed relay lVlF (all shown in Fig. 9), a hand index relay HI, an automatic timing or interlock contactor ATC, and a. master timing or interlock contactor MTC (all shown in Fig. is). In. the case of the various motor contactors all of which are shown in Fig. 9, the contacts therefor have been shown as mechanically connected (indicated by broken lines) with the actuating windings therefor. In the case of the other contactors and relays the reference characters for the same have been applied to their actuating windings and their contacts have been shown immediately adjacent the actuating windings. These immediately adjacent contacts are not, however, shown at such point as connected in the circuits but are repeated in the. proper points in the circuit. The individual contacts of the various relays and contactors are identified with the reference character for the particular contactor or relay preceded by a digit for the particular set of contacts. Thus, for example, the master start relay MS has contacts lMS, EMS, etc., which are shown in the upper right-hand portion of Fig. 9 immediately adjacent the actuating winding of the relay and repeated at their proper points in the circuit.

Re'sum of programed automatic operation As a preliminary to programed automatic operation of the machine, the following initia1 settings of the machine elements and controls must be made:

(a) The master controller lever 22 (Fig. 2) is shifted to its automatic cycle position (Fig. 12) thereby closing controller contacts Cl and C2, while leaving C3 to C1 open. In the wiring diagrams of Figs. 9 and 10 these various contacts of the main controller have been shown in such condition.

(2)) The program selector lever 9| (Fig. 6) is moved, to condition for operation, a selected one of the alternatively available sets of cams 83, 84. It will be assumed in the succeeding description of the machine that the set of cams B3 is the one first conditioned for operation. The program chart constituting Fig. 11 designates the various ones of the cam-operated switches which are closed in successive steps of the first and second programs, corresponding respectively to the two sets of cams 83 and 84. As appears in the first column of the chart of Fig. 11, the table I has fourteen index positions and is finally returned to the fourteenth position as its final rest position. In each of the resultant fifteen rest positions of the table in making a complete revolu-.

tion (the first and last of which are the same),

16 fifteen different operations are performed (see second column in the chart) by the various designated units. A black square in the chart indicates that the corresponding switch is closed and a white square that it is open.

(0) The units l to 6 must all be returned to their fully retracted positions, in which event the main contacts of the switches LSI l, LSZl, LS3I, LS i I LS5 l, LSiil are all closed.

(d) The table i must be positioned in its proper starting position, that is, the location corresponding to position No. 14 in the chart of Fig. 11. In such case, the switch LS'H (Fig. 10) will have been closed momentarily in advancing the table to such position and, assuming current to be available in the supply lines, the master timing contactor MTC will also have been momentarily energized (being connected across lines HS, Ill

hrough switch LS? and will have momentarily closed its contacts lMTC. Closure of these contacts will have momentarily completed energizing circuits for the release coils of timing contactors Tl, T2 and T4. Thus, release winding TCl will have been connected across lines I l 6, i ll through contacts IMTC; release winding T02 will have been connected across these lines through contacts IMTC and switch L822; and release winding TCA will have been connected across the lines noted through contacts llVITC and switch LSAZ. Consequently, the interlock contactors Tl T2 and T4 are unlatched preparatory to the first step of cycle in the program.

Having preliminarily conditioned the machine for automatic operation through its first program as noted above, the operator starts the various unit drive motors 25 to 30 by momentarily closing the start push button switch A (Fig. 9). Such momentary closure of this push button switch energizes the main starting relay MS (through a circuit I l 5-B l-ML.-K-JI-H--l I 8-A il9MSl loB) so that this relay closes all of its eight normally open sets of contacts. Of these IMS closes in shunt with the push button switch A so that the relay is sealed in, contacts ZMS to EMS connect the actuating windings of the respective motor contactors Ml to M6 across the lines H6, H7 so that these latter contactors are all pulled in and set their respective motors 25 to 30 running, and contacts EMS close to preliminarily set up a portion of the energizing circuit for the indexing motors contactors, though such circuits are not completed at this time. With the unit drive motors thus running, and the machine preliminarily conditioned as described, the pilot lamp H i will be lighted, ap-

prising the operator of the fact that the machine is ready for institution of its programed automatic operation.

To initiate the automatic operation of the machine, the operator momentarily closes the cycle start push button switch C, thereby energizing the automatic feed relay AF by connecting it across lines H5, H6 (through ll5-LS6lLS5I LSM --LS3l LS2I LSII C--AF-5T3-- 2LS8ZI H5) Thereupon, this relay momentarily closes its contacts IAF, whereby the unit forward solenoids IJFl, UFZ and UF4 for units l, 2 and A are correspondingly momentarily energized. Thus, closure of these contacts IAF connects a supply line I21] (which is connected to H9 and thence back through IMS, H8, H to M, and Bi to line M5) to a line l2l. The unit forward solenoids UFl, UFZ, UF l and UF5 are connected between this line I2l and line I I6 through their respective interlock contactor contacts ITI,

i7 t'IZ, 1T4 and IT5. Qf theselatter contact ITI, [T2 and [T4 are closed, in the present instance,

due to the energization: of; their respectiverelease.

coils as heretofore noted, sothat momentary closure of contacts IAE effects a resultant energize/- tion of solenoidsUFl, UF-Z; and U 4.

As was heretofore pointedout, the momentary energization; of the, unit forward solenoid; ofv any of the units throws its associated valve mechanism into a position to eifect a rapid advance of the unit. Accordingly, the energization of; solenoids UFl, IIFZ and UF4 causes the corresponding units L2 and 4: tostart a rapid ap: proach movement. As thismovement progresses, the dogs 31 therefor (see Fig, 3) actuate, the corresponding plungers 36 so that their valve mechanisms areshifted to: a feedP-hositionand the rate of advance of the unitsis diminished to a. slow feed rate. During. this slow feed advance of the units l, 2' and. 4, their tools operate uponthe. Work piece. At the conclusion of the auvancing or feed. movements ofthe units I, 2' and 4:,the clogs 39 thereon trip their correspondingreverse limit, switches L513, LS2} and L843 (Fig, 10), closing the same. losure of, these three switches serves respectively to connect the relays U'I'RI, UIRZ; and: UTRII across the lines H6, Ill; thereby picking up, these relays. Each of these relays has two normally open contacts, the first of which serves to. close an energizing circuit for the respective unit reverse solenoid, and the other of which serves to. complete an energizing. circuit. for the main winding of th corresponding interlock contact to latch it in. Thus, for example, closur of; contacts tUTBI; connects: the solenoid RI 31 7 85 es '6; 1' to energize it, and: closure of contacts ZUTRI; connects winding TGMl: across lines H6, Hz! to. energize the latter" winding; and thereby latch in the interlock contactor Tl. In this way, the reversing solenoids UB5, UB4 for the three operative units are actuated to shift the. valve mechanism therefor to their rapid return positions and at thev same time the interlock contactors- Tl, T2 and T4 therefor are relatched for the interlocking purpose heretofore described. It will beunderstood that as soon as the units actually reverse, they release their switches L553, L823. and LSdSi so that the latter reopen and drop. out, the relays UIRla, UTR 21 and U'I-Ri l. That is as it should be, however, since these relays have already done their Workat that time and the circuits are thus conditioned; for sub-. sequent operation.

Aseach of the units IJ, 2 and 4 finally reaches its initial: or retracted position, it is stopped. by engagement ofits corresponding dog 38 with the valve plunger to: which shifts the valve mechanism to itsneutralor stop-position, At the same time, the dogs'HlZ! of the respectiveunits close their corresponding unitinterlock: switches LS! L LS2 I and LSM.

When all three of the units have, been re.- stored in this manner to their initial; positions, the series of switches LSlit, LSZlz, L831, LSAI, LS! and L865: will all have their main contacts closed (Fig; 9:) and; furthermore, all of. the interlock contactors T1 to: T6 will be latched in. With the circuits in the latter condition, the index motor for the table 1' is automatically started. In particular, its. forward-f contactor IMF is connected across lines H5,. H6 (through a circuit ljl5-1136l:+LS5-l;-LS4;lrLSitl+LS2TI:- LSI I- l:2'2+B2. 2Tt-..ZT,2-- 2T3:-2.'I4;-.- 2.I-.5.. 2TEIMZET-l l6); Observe that the series of contacts ZTl. to. @536- in the:- latter circuit makes, it imperative that all. or the interlock contactors. TI to T6 be properly latched in, as heretofore. noted,v before the circuit can. be completed to start. the index motor, and. that the inclusion, of the unit switches; makes it imperative that all. units be: fully; retracted. Such energization of. the "forward con-tactor IMF for the index motor td picks up, its main. contacts, Whichconnect. the motor to; the supply lines for forward. rotation. of the; motor, and in addition opens the com tactors auniliary contacts IIMF and closes the auxiliary. contacts 21MB; The opening of, the. contacts lTME prevents energization. of the reverse contactor- IMR. when, the plugging switch '54 closes during the forward rotation of the index motor; the initial. open. condition: Qt th s. plugging switch having prevented previous energization. oi the reverse contactor IMR.

Aethetable'l' indexes, the. switch LS1; is freed by its. dog- 15 (see Fig. 5,) and thereupon closes so; that a;- circuit iscompleted through this. switch and the contacts; Zl-MF in shunt with the series ofcontacts. 2T1, to, 27175, with the result that the forward co ntactcr IMFv is retained. energized through this shunt circuit even though some, oi

the, interlock contactors: are unlatched, as they are, in anticipation of the nest step, in. the Pr ram-- on c mp io f;- thead x nem me Oi t e b e: the. SW fi l: n a d by dog l5, and; opens. This; deenergizes; the for-. ward? contactor IMF, whereupon the contacts HMFclose. Accordingly, the reverse?! contactor 1MB is; energized, being connectedbetween lines 1 l6 and H1 throughhMS, I I MF and the plugging switch 64'. Assoon as the; index, motor llllstarts to revolver in. a: reuerse direction, however, the plugging switch (it\ opens automatically in the manner heretofore: described, whereupon, the reverse contactor 1MB; drops out; and the index motor isa-t a standstill;

In the course of the indexing of the table the circuits. are iminarily e p or h sli il tion of unit movement in the; next step or th program. Before detailing this operation it should benotedthat the first, step oftheprogram was initiated; as described before by energize: tion. of the rel lll As; will appear below, the subsequent steps in the program are initiated, not through this; relay, but; through the medium of the relay ME; This shiftv from one intermediate relay to. the other is accomplishedby the cam-ope ated switch L332. shown in the program chart of Fig. 11, the contacts l-LSBZ of this; switch are. open: during; the first step of the program and closed d rin he b uent steps, while its contacts 2Ls82- are closed during the first. step. an p n.- du ie h sub quen steps, being reclosedat. completion of the pro: ram. The. contacts: ILSBZ onnect i the re a ME" and the; alternatively closable contacts ZLSQ? connect in the other relay AF; Such. a switching arrangement, that is, the alternate, use of these relays Aliand ME- inthe manner noted, introduces a desirable. safety feature in the system, in'thatan inadvertent or inadvised closure of the cycle start? push button 0. during the oma ic lt at on th m i a no cause it to, recycle, since the cir U-il; or the relay (in series withwhichthe push button C is con-,- nected) is retained open by the contacts 211583. At the. completion of: the program; howe r; the op ning; or contacts thSBZ drops; out the rela Mr and the; closure. of: contacts met-2 resto es 19 the relay AF to its initial condition in the system for the initiation of another program when desired.

As to the particulars of the switching operations which take place automatically during the indexing of the table, it will be recalled that the cam shaft 82 is indexed in unison with the table. Hence, the cam shaft is turned from its first to its second position during the first index of the table, whereupon cam-operated switches L822 and LSLIZ, which are closed during the first step of the program, are opened, as indicated in the program chart in Fig. 11. This is done since only unit I is scheduled to participate in the second step of the program. Furthermore, as the table indexes, the switch LS'II closes momentarily, being actuated by its dog I8 (see Fig. as before. The closure of the switch LSII momentarily energizes the master timing contactor MTC, but this time only the interlock contactor TI will be released, since all of the cam-operated switches controlling the other interlock contactors are now open. In this way, the unit I, which is the only one scheduled for the second step in the program, is conditioned for operation.

At the conclusion of the indexing of the table, the operation of unit I is instituted for the second step in the program. For this purpose the switch L813 is closed momentarily by its dog I4 (see Fig. 5) after shaft 44 has turned far enough to index the table and just before it has completed a full revolution. At the same time, if the locating pin 53 has been properly engaged with the table, the contacts 2LS'I5 of the dog operated switch 2LSl5 will also be closed. Thereupon, an energizing circuit for the master feed contactor MF (Fig. 9) is momentarily completed (through LS'I3, ZLSIE and ILSBZ). When this relay is thus picked up, it closes its four sets of contacts IMF, ZMF, SMF and 4M1. Of these, IMF are relay contacts in shunt with the switches LSI3 and 2LS15 so that the relay MF will remain energized even though switch LS'I3 reopens before the index shaft 44 completes a full revolution; contacts 3MB and 4MB are associated with the starting circuits for units 3 and 6, and hence perform no useful function during the second step in the program in which these particular units are not included; and contacts ZMF complete an energizing circuit for the unit forward solenoid UFI for unit I.

The operation of unit I having been instituted in this manner it proceeds to execute its cycle of movement in the same manner heretofore described. As soon as the unit starts forward it releases its switch LSII so that contacts ILSII of thelatter open and drop out the relay MF. When unit I reaches its forward limit of movement, its interlock contactor TI is relatched in the same manner heretofore described in the first step of the program, and at the completion of the cycle of unit movement the unit is stopped by dog-operation of its valve mechanism and its unit switch LSII is reclosed, whereby to complete a starting circuit for the indexing motor 40. Then this latter motor indexes the table I through its next step of movement and it is automatically stopped in the manner previously described; and durin this indexing motion the switching system is conditioned for the next succeeding step in the program.

The machine proceeds automatically to execute the subsequent steps in the program in substantially the same manner with an indexing advance of the table between each step. The program'chart in Fig. 11 indicates the units, in addition to the unit I, which participate in each particular step, the unit I being omitted from the chart since it is included in all steps in the first program. In particular, the units I and 2 participate in the third step of the program, the unit I alone in the'fourth step, the units I and 2 in the fifth step, the unit I alone in the sixth step, the units I and 2 in the seventh step, the unit I alone in the eighth step, the units I and 2 in the ninth step, the unit I alone in the tenth step, the units I and 2 in the eleventh step, the unit I alone in the twelfth step, the units I and 2 in the thirteenth step, and the unit I alone in the fourteenth step.

At the conclusion of the fourteenth step, the unit I is, of course, retracted to its initial position and the table I automatically indexed to its first or initial position to complete a full revolution. Duringthis last index step of the table, the cam-operated switch L882 is thrown so that its contacts ILSBZ are opened and its contacts ZLSBZ closed (see chart in Fig. 11). Consequently, the relay MF is dropped out, thereby preventing inadvertent recycling of the machine, and the closing of the contacts 2LS82 lights the pilot lamp III and conditions the circuit of the relay AF for subsequent completion by closure of the push button switch C to institute another complete program when desired. It will thus be seen that the machine comes to rest with all of its control devices in their initial condition.

The same program described above can be repeated on another work piece in the same manner described, if desired, or the machine can be run through its second program to operate on the same or a different work piece.

To condition the machine for the second program, the operator has only to shift the lever 9| (Fig. 6) to the right so as to bring into play the alternative set of switch operating cams 86. Having thus conditioned the machine for operation through its second program, the automatic operation is instituted as before simply by a momentary closure of the cycle start push button switch C (Fig. 9). Thereupon, the machin will proceed to operate through the second program, outlined in the chart constituting Fig. 11, in substantially the same manner as for the first program, except for the last step. In particular, during the second program the units I, 2 and I participate in the first step, the unit I alone in the second step, the units I, 2, 3 and 5 in the third step, the unit I alone in the fourth step, the units I, 2 and 3 in the fifth step, unit I alone in the sixth step, the units I, 2 and 3 in the seventh step, the unit I alone in the eighth step, the units I, 2 and 3 in the ninth step, the unit I alone in the tenth step, the units I, 2, 3 and 6 in the eleventh step, the unit I alone in the twelfth step, the units I 2, 3 and 6 in the thirteenth step and the unit I alone in the fourteenth step.

After the operation of unit I is completed in the fourteenth step of the second program, as noted above, the table I is indexed automatically to its initial or starting position. As in the case of the first program, the switch LS8I is actuated so that the relay MF is dropped out and the relay AF conditioned to start a new program. In the case of the second program, however, it is desired to have the unit 3 operate on the work piece after the table has thus been returned to its initial or starting position. Such operation poses a diffibe dropped out to'prevent inadvertent recycling. It isto overcome this difficulty, and make possible the operation of a unit after the table has been indexed a full revolution, that the cam-operated switch L583 is utilized. Upon reference to the program chart Fig; 11; it willbe seen that this latter switch is closed only during the second program and then only when the table is in its starting or No. 14 position. I

Closure of the switch LS33 (Fig. 9)'- sets up an energizing circuit for the unit forward solenoid- TF3 for the unitt which is independent of the contacts of the relay In particular, the solenoid. UFS- is connected from the supply line H6 through the interlock contactor contacts lT3 (this contactor having been unlatched during the preceding indexing step efthe table) and-thence through switch LSBB, switch contacts ZLSIE and switch LSlt to the line I I1; It will be recalled that the switch: contacts ZLSlEl are closed only whenthe locating pin53 is properly engaged with the table, thereby indicating that the table is properly positioned and that switchLS'lB is inomentarily closed by the table indexing or drive mechanisms shaft 44 to normally institute oporation of a selectedunit or units. At the ccmpletion of the forward movement of the unit which results from the energization of its unit forward solenoid UES, the interlock contactor T3 is unlatched, in the manner heretofore described, so that its contactors iTt open and deenergize the solenoid U E-3, in addition to energizing the reversing relay UTRB (Fig. 10) in the manner heretofore described. At the completion of the retraction movementfor unit the dog operation of its valve mechanism stops the same and the machine is thus at restin its initial condition.

Attentionshould be givenat this point to the arrangement by means of which it is possible to cause the unit 3 to operate, as described just above, when-the table returns to its final or initial position, and yet participation of unit '3 in the first step of-thesecond program is prevented. In other words, the second program presents this dilemma: Onlyunits I, 2 and 4 are to participate in the first step of this program, when the table is in its initial position, and yet during the secnd time that the table is again in this initial position (i. e., at the end of the program) only the unt '3 is operated. It was pointed out above that the relay MB is dropped out and the switch L833 used tocondition for operation the. unit or units (in the present instance only theunit- 3) which are to operate when the table isin its initial position for the. secondtime. Upon the institution of the second progra-mof operation, the unit 3 isexcluded from participation by virtue'of the fact that this first stepof the program is initiated through the medium of the relay, AF, and the contacts lAF of this relay do not set up a circuit for the unit forward solenoid 'UF3 for, unit 3 (Fig. 9).

It will, be observed upon reference to Fig. 9 that the interlockrcontactor T3 for. unit 3 has an extra pair of contact T3 in series with the lamp H l and :cyclestart switch C. These contacts areopen when thelcontactor T3 is unlatched and, hence disable the machine against institution of anew cycle, byclosure offthe switch C while unit an moving, forwardl duringgit s ecial operation at the end of the second program.

The; machine can be stopped at will during either ofthe foregoingprograms of automaticoperation simply by momentarily opening the stop push button switch B'- (Fig, 9). This switch is normally closed and is interposedlin the control supply-line H5. sinceallof the: co tactors, relays and solenoids are supplied through this line H6, opening-ofitwill'drop all of them out, thereby stopping all-of the motors 25 to- 3H and so; The propulsion-mechanismsfor the various units will stop, irrespective or them-- sitions' oftheir control valves, since-the motors 25 to 3% supply pressure fluid for them.

In the foregoing"descriptionof automatic operation, it wa assumed that the various units properly-executeditheir corresponding cycles so. that: the. interlocle mechanismswere not compelledtowinterrupt the. operation. It willbe a epreciated, however, that if any. of the unit had failed to move forward fully, their, interlock .cone tactors'li to 'Ifi would have -fai1ed to be latched and consequentlyone of the series of contacts 2511i, to Z'I'fiwouldhave been open, thereby. preventing the. nextT indexing step of the. table. Upon such aiailurecof the table to index, theop-v era-torshould closethe push button switch N..(Fig, iuland thepilot lamps liawould thereuponind-icate which one o-f-theunits was at fault. Similarly, if. any 01": the unitsfail fully. to retract, the main contacts. of. the corresponding. one of the series-.of switchesLSil, LS2], LS3l, L841, L651, LS5! wo-uld'be open so that,.ag.ai-n, the table would not index. Insuch event, the operator should clos,e.{the push. button switch 0 (Fig. 9) whereupon the. pilot lamps l E3 will indicate which. oneof the units .isat fault.

Finally, if anyof the units shouldstart forward before the table I is properlypos'itioned, the 010-.- sure of one. Or the other of the switches LS1 4 or LS35 would cause an emergency retraction of all of the units. It will be recalled-thatthese latter switches-are. closed, respectively, by the corresponding dogs onunits I and '3, and that one or. the. otherv of these units participates in each stepof both programs. These-switches (Fig. 9) are connected inseries with the switchcontacts iLSlB which, it willbe recalled, areclosed whenever. the table is not positioned by itslocating pin 53 in one of 'its proper index positions. Accordingly, if switch LSM or LS35is closed coincidentallywith contacts ILS15, the emergency retract relay. ER will be connected across lines H6, H1 and energized. This. relay has contacts IER, ZER, SER, 4ER, 5E,R, BER. (Fig. 10 connected in series with respectiveones of the unit reverse solenoids URI to UB6. Consequently, energizationof the relayER causes all ofv these reversing solenoids to be energized, whereupon the unitsare eachset forreverse operation as heretofore noted. The provision of this safety interlock for. retracting the units under the conditions noted is especially desirable here, since to speed up machineoperation the switch LSl3 for instituting unit forward motion is, as here-,- tofore noted, closedmomentarily after the table has indexed but before the index mechanism has actually stopped, Hence, no danger can arise even if the index drive mechanism should inadyertently overrunand shift the table after, the units had started, for the latter would be retracted by the action of switches LSM and L835, just described. In this connection it will be observed that only about one hundred and twenty degrees of the rotation ,ofithe index shaft. is used in indexing the table and'the remaining two hundred and forty degrees of each revolution of this shaft used to operate switches. Though this The hand feed operation of the machine is of a type which may be termed semi-automatic in character, and is used to effect a repetition of the operation of the units in a desired step of the program. Such a control is, of course, especially useful in the set-up of the machine for a new type of work piece. In using this so-called hand feed the table must have been indexed to the desired position by the automatic cycle operation of the machine and then stopped by switch B (rather than having been positioned by use of the hand index control) so that the unit-selection portion of the circuit will be properly set up for the selected table position. With the master controller lever 22 (Fig. 2) thrown to its hand feed position, the machine is conditioned so that a momentary closure of the hand feed push button D will cause those units to execute their automatic cycles of operation which are programmed for operation in the particular position in which the table I has been located by interrupting an automatic cycle of operation at a desired point, Thus, if the table has been shifted as noted into its No. 3 position (chart Fig. 11) for the first program, units 1 and 2 will be conditioned to execute their cycles of movement upon closing the hand feed switch D, but at the completion of the same no indexing of the table will take place, as contrasted with the operation heretofore described during automatic programing. This hand feed style of control can be used for any position of the table except its first or initial position, the circuits being such as to exclude operation of the units by the switch D when the table is in that position.

When the master controller is thrown to hand feed position its contacts Cl remain closed just as in the automatic cycle position, but its contacts C2 are opened and its contacts C3 closed (Fig. 12), The contacts Cl are retained closed so that closure of the main start switch A will start all of the unit motors 25 to 30 just as before (Fig. 9) The controller contacts C2 are opened to out the index motor 40 out of service; and the controller contacts C3 are closed to put the hand feed switch in service.

Upon reference to Fig. 9 it will be observed that the switch D is connected in a branch circuit between the master feed relay MF and line H5, which branch circuit includes a group of interlock contactor contacts lTl to 4TB (all in parallel with each other) the master controller contacts C3 and the series of unit limit switches LSH, L829, etc. This branch circuit is, in effect, in shunt with the switch L813 that was used in the automatic cycle operation to energize the relay MF to institute unit movement in all steps of the automatic program except the first. Accordingly, momentary closure of the push button switch D, during the hand feed operation is used, instead of LS13, to pick up the relay It will thus be clear that whenever the switch D is momentarily closed the relay. lVEF will pick up, seal itself in, and cause energization of the unit forward solenoids for the units (preselected by the unlatching of their contactors TI to T6 as the table shifted into the position which it happens to occupy). Thereafter these units automatically execute their individual cycles just as before. Recycling is prevented since the relay MF drops out as soon as one of the units starts forward and opens its corresponding one of the series of switches LSl l, L824, etc. The index motor has been cut out of service by opening of the controller contacts C2 as heretofore noted, so when the units come back to their initial position they remain there and nothing further happens until the operator again presses the switch D, whereupon the same units will again repeat their same cycles of movement. This can be done over and over again in adjusting them for some particular step in the program.

Individual unit feed operation When the master controller is shifted to its third or unit feed position, the various units can be operated individually with manual control I thereof. In this position of the controller only its contacts C4 are closed (Figs. 9 and 12). These contacts connect line H5, through the interlock switch LS'M, to a group of push button switches H to M corresponding, respectively, to the several units l to 6. Accordingly, closing any one of these switches picks up its corresponding motor contactor Ml to M8 and starts the one of the motors 25 to 3!! for the associated unit. The motor can, of course, be stopped at any time by reopening the corresponding one of the push button switches H to M.

When the motor of a desired one of the units has been started as described above, the hydraulic propulsion mechanism of the unit can be controlled by the hand lever 34 (Fig. 3) on its valve mechanism to move the unit to and fro as desired. Since, as heretofore noted, the switch LS'M is only closed when the table l is properly positioned in one of its several index positions, such manually controlled operation of the units can only be utilized when the table is safely and properly positioned.

Hand index The hand index operation of the present machine is arranged to make possible indexing of the table '1 without operating any of the units l to 5. Preferably, the arrangement is such that the institution of hand indexing serves automatically, as below described, to cut out of service the programing controls for the various units, and in the present instance, this is accomplished by automatically unlatching all of the interlock contactors T! to T5. This disabling of the program controls during the hand index operation makes it possible to use the unit feed control freely in various positions of the table to which it is hand indexed, and as the units are moved by unit feed, any resultant operation of the limit switches, etc., will not disorganize the set-up for later automatic cycle operation. One result of the unlatching of the interlock contactors TI to T6 by the hand index operation is, however, that all of their contacts 4Tl to 4T6, in series with the hand feed switch D are opened (Fig. 9) so that the latter switch is disabled. It is for this reason, as heretofore noted, that for a hand feed znas ees operation the table must be moved to a desired positionby the use ofthe automatic cycle controls-and not by the use of the hand index con- .trols. 1

Although the hand index operation of the machinedoes result in unlatching all of the interlock contactors TI to T6, thereby disabling the program system, provision is made for restoring the program-controls to their proper condition for institution of a program of automatic operation whenthe table 1 is indexed into what is its initial position tor such a program. In particular, the automatic timing contactor or relay ATC (Fig. is arranged in a manner detailed below to be cut into service during hand indexing, when the :table is indexed from its next to :last position to its initial position, andthis contactor;ATC serves to latch in the ones of the interlock contactors TI to T6 which correspond to the non-participating units for the first step 'of the program. Consequently,'the'machinecomes to rest'after the hand indexing with the table in its initial position and with the interlock contactors for only the units which are to participate in the first step of the program unlatched.

Turning now to the details of "the circuits uti- 'lized during hand indexing operation (Figs. 9 and 10)., the master controller is shifted to its hand indexing position, thereby closing contacts C5, C6 and C? and opening contacts CI to C 3 (see Fig. 12). Upon reference to Fig. 9 it will be seen that the contacts 05 and C6 are interposed in the circuit of the forward contactor -I of the index motor 40, and upon reference to Fig. 10 that the controller contacts C1 are includedin the circuit of the handindex relay HI. 'Up'on closure of the hand index push button switch E (Fig. '10), the relay -HI is energized through-,contacts l-LS-Bl of the switch LSSI. When the relay 'HI thus :picks up, it closes its contacts-= lI-II (Fig. 9) to energizethe index motor contactor IMFand also closes its contacts -2I-II to 'iHI (Fig. 1 0) to energize the release windings TCI to TCS of the interlock contactors TI to T6, the latter being connected between line H6 and a line IZI. I-he interlock contactors are thus all released to disable the-programcontrols, and the index motor 4i is-energized for rotation in-a forward direction. 'l 'he index motor is retained energized in this manner so long as the switch E is 'held closed, so that the table is rotatably indexed step by-step. Fin-ally, when the tablereaches its position No. 13 (chart-Fig. 11) the switch LS8] is shifted so that its-contacts 'I'LSH open and its contacts 2LS8! close. Such shifting of the switch LSB'I drops out the relay I-IIand picks upthe contactor or relay A'I'C. Energization ofthislatter contactor causes to-close its contacts IATC (Fig. 9) in shunt with the contacts 1H1 to retain the index motor 49 energized and to close its contacts ZATC, 3A'IC and AATC for energizing, respectively, the main windings TCMS, TCM5 and TOMS of the interlockcontactors T63, T65 and 'ICito latch the latter in. Consequentiy, \vhen the table 1! reaches its No. 14, -or initial, position, the interlock contactors T! to T6 will beset-up as they should be for subsequent institution of an automatic cycle. In-other words, only thecontactors'for the units l, 2 and l, which-are scheduled to participate in the first step of the program, are unlatched.

From the foregoing it will be clear that the table can be revolved as many times as desired with'theuse of the hand-index control, but that whenever it is located in what is its initial position for the automatic cycle, the program control.

26 .portionof the circuits will be properly conditioned for institution of thelatter type of operation.

I claim as my invention:

1. In a multiple station machine of the character set forth, the combination with indexible work positioning means, a plurality of tool units reciprocable toward and from the work, and a control system including a programing mechanism governing the operation of said units selectively in successive operating cycles in timed relation to the advance of the Work by said positioning means, said positioning means including an actuator, and said control system further including a :pair of--control devices for each of said units, one operative to detect the advance of the unit into engagement withthe work'and the other to detect its retraction from the work, the control devices '01" the several units coacting with said programing mechanism to prevent operation-of said actuator in the event of failure of performance of any of the units preselected for operation *by the progr'aming mechanism in the preceding cycle.

2. A'machinetool comprising, in combination, :a work support and a tool support, first .power actuated means forindexing one of said supports and a second .poweractuated means for eflecting a cyclic relative movement between said supports including advanceand retraction of said supports relative to eachother, first and second switches, means forclosing said first switch in response to completion of :a predetermined relative advance of said supports by said second power actuated means, means for closing said second switch in response tocompletion of a predetermined relative retraction 10f said supports by said second power actuatedmeans a control circuit including both of said switches, and means for automatically instituting indexing of said one support by said first :po-wer actuated means "in response to completion of said control circuit by closure of both of :said switches.

3. A machine tool comprising; :in combination, a work support and a tool support; a first power actuated means for indexing one of said supports anda second power actuated means for effecting a cyclic relative movement between said supports including advance andretraction of said supports relative to each other; an interlock contactor *having'a main winding, an armature shiftable in response to energization of said main winding, means for mechanically latching said armature in the position to which it is shifted in response to 'ener'gization of said =main winding, a release winding operable -upon energization thereof to release said latch, and means for normally urging said armature out of latched position; control means for initially energizing said release winding :to unlatch said armature; means responsive to the completion of a predetermined relative advance of said supports toward each other for momentarily energizing said main winding to relatch said armature; means operable in response to completion of a predetermined relative retracting movement of said supports to initiate operation of said first power actuated means to index said one support; and means for preventing operation of the last-mentioned means except when said armature 'is in its latched position.

4. A machine tool comprising, in combination, a work support and .a tool support; a first power actuated means for indexing one of said supports and a second .power actuated means for elfecting a cyclic relative movement Jcetween said supports includingzadvance and retraction of said supports with relation to each other; aninterlock contactor 

